Discharge device



March 2, 1943. D. MARSHALL ETAL 2,312,350

j DISCHARGE DEVICE original Filed sepnnfze, 'i940' INVENTORS i m i K n. 5W DM Patented Mar. 2, '1943 DISCHARGE DEVICE Donald E. Marshall, Allwood, and William J.

Knochel, Irvington, N. J., assignors to Westinghouse Electric & Manufacturing Company, East Pittsburgh, Pa., a corporation of Pennsylvania Original application September 26, 1940, Serial No. 358,474. Divided and this application April 18, 1942, Serial No. 439,574

vs claims..l (o1. 25o-27.5)

This invention is a division of our prior application directed toa metal-casing discharge device, Serial No. 358,474, filed September 26, 1940, entitled Discharge device with water cooled baffle, the present invention likewise relating to discharge devices, and to such devices utilizing metal casings.

An object of the invention is to provide improved means for mounting the anode within said casing.

A further object of the invention is to obtain an insulative mounting of improved and more rugged character than has heretofore been accomplished. v

A further object of the invention is to provide an easily assembled structure of metal casing and anode insulated from said casing.

Further objects will appear both by direct recitation thereof and by implication from the context as the description progresses.

In the accompanying drawing, the single view shown is a partial elevation and longitudinal section of a discharge device constructed in accordance with the present invention.

In the specific embodiment of the invention illustrated in said drawing a tubular closed and evacuated inner casing i'is provided preferably constructed of stainless-steel Eand represented in conformity with the showing of the said prior application, to which reference may be had for details not here shown as not deemed essential to the understanding of the present invention. Suffice it to say, that the said casing I is shielded at its cylindrical wall with an outer casing I2 spaced from the inner casing to provide a cooling space I3 between the casing. The feature of the present invention is not dependent upon the presence of the cooling space, reference being made thereto at this time merely to orient the present invention with respect to the aforementioned application.

The upper portion of the closed casing I has a bent-out marginal end portion I4 which engages the outer casing l2 and is secured thereto entirely around the periphery.

Below the flared out portion I4, is provided a dish-shaped upper header member I5 which constitutes part of the end closure for the said casing. This header member is preferably trough shaped, with the flanges of the trough directed outwardly. The outer flange is welded,l as at I6, to the casing entirely around the periphery so as to obtain a vacuum-tight seal. The inner flange, which is annular and in parallelism with the outer flange, provides a central opening I1 CFI y anode and said header.

.for passage therethrough of the stem portion I8 of anode I9 situated Within the casing in proximity to the said header I5. The size of the opening I1 within the inner flange of the header is ample to obtain insulative spacing of the stem portion IB of the anode inwardly out of contact from said header flange. The header I5, like casing Ill, is preferably made of steel. It is desired to support the anode fro-m this steel and to obtain a vacuum-tight seal as well as a permanent seal and adequate support. There is no known insulative material which will accomplish the purpose directly by inclusion between the The differences in the coeiiicients of expansion must be considered, as those differences are inclined to cause cracks and crevices.

According to the present invention, a tubular member constituting a collar 2U is secured with a lower margin of itself engaging the inner cylindrical surface of the hole-forming flange of the header. This collar is preferably of nickelcobalt-iron alloy sold under the trade name Kovan This material is strong, but expensive, and is accordingly employed in minimum amounts both as to thickness and length in 'formation of the collar. Where the cylindrical surfaces of the collar and header flange arel juxtaposed or in surface contact, the same are secured together, as at 2l, so as to obtain an adequate Vacuum seal and support. The upper marginal portion of the collar projects above the header flange and mounted therein is a cylinder of borosilicate glass 22. The coeflicients of expansion of the glass and the Kovar collar are substantially the same, and by sealing the glass to the Kovar a permanent union is obtained with little, if any, likelihood of ruptures occurring at the joint. At the upper end of the cylinder of glass 22 the outwardly curled edge of a cup 23 is similarly sealed, said cup likewise preferably being a nickel-cobalt-iron alloy such as heretofore described and identified as sold in the trade under the name of Kovar The bottom of the cup is reentrant with respect to the cylinder of glass 22 and is flat on its bottom for conveniently securing the upper end of anode stem I8 thereto. The Kovar cup and collar are both of adequate strength to absorb the stresses and strains resultant from differences in coefficients of expansion therefrom of attached parts, and since there is practically no stress between the Ko-var parts and the glass cylinder, likelihood of rupture is thereby avoided but at the same time a rigid nsulative support is provided from the header to the anode.

It is apparent that many modications may be made in the preferred structure illustrated and, accordingly, we desire only such limitations to be imposed upon our invention as are necessitated by the spirit and scope of the following end of said insulative member and having a vacuum-tight seal therewith, said means supporting the anode and having a part thereof which under expansion moves the anode opposite forming a part of the closure for said casing, said casing and header being constructed of like materials, an unlike material secured vacuum tight to said header and likewise forming part of the closure, and an insulative member carried by the last-mentioned member and having substantially the same coeicient of expansion thereas, and a cup having a curled edge sealed to the upper part of said insulative member, said cup being reentrant into said insulative member and supporting the anode.

3. A discharge device comprising a tubular casing, an anode within said tubular casing, a conductive support extending through the upper end of said tubular casing, insulation encompassing a part of said support and having aty tached connection therewith, a tubular member to movement thereof due to expansion of the collar.

2. A discharge device comprising a closed tubular casing, an anode within said casing, a. header sealed to said insulation and extending into said tubular casing and an annular trough-shaped header having its inner flange secured vacuumtight to said tubular member and its outer ange secured vacuum-tight to said tubular casing.

DONALD E. MARSHALL. WILLIAM J. KNOCHEL. 

